White Ensign n (Nautical Terms) the ensign of the Royal Navy and the Royal Yacht Squadron, having a red cross on a white background with the Union Jack at the upper corner of the vertical edge alongside the hoist. Compare Red Ensign, Blue Ensign Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014